1. Field of the Invention
The present invention relates to the field of spray devices. More particularly, the invention relates to a method and apparatus for directing a mist stream with a predetermined diameter to a target location at a predetermined distance from the spray device. In an aspect of the invention, said method and apparatus are included in a method and apparatus for cooling cattle, by means of coordinated groups of spray devices, which are used in a controlled manner that accounts for environment conditions. Particularly, though not exclusively, said cattle are cows and the cooling is carried out when the cows are housed in a shed and the relevant environment conditions are defined by the prevalent wind streams.
2. Prior Art
One of the requirements for high milk production in summer is relieving heat stress. Several studies have determined that milk production can be increased by installing cooling systems. (“Interactions Between Body Condition at Calving and Cooling of Dairy Cows during Lactation in Summer,” Flamenbaum et al, Journal of Dairy Science, Vol. 78, No. 10, 1995 and “Dry Period Heat Stress Relief Effects on Prepartum Progesterone, Calf Birth Weight, and Milk Production,” Wolfenson et al, Journal of Dairy Science, Vol. 71, No. 3, 1988). A side benefit to the installation of such cooling systems is that the reproductive performance of cows can be improved with cooling.
A prior art cooling system generally consists of an air distribution duct for directing a turbulent air stream onto the cows and a separate water line that terminates with a nozzle which produces a spray. Nozzles are commonly used, in contrast with discharge directly from a hose, to conserve water. Sprinklers that are positioned in the feeding area of a dairy farm generally provide supplemental cooling, reducing the fan power needed and enabling a marginally hot cow to be much more comfortable. Since cows sweat only one-tenth as much as humans, a spray-fan cooling system conducts away surface heat and increases the vaporization of moisture from the skin. This body cooling effect enhances comfort and increases milk production.
U.S. Pat. No. 5,643,082 discloses an apparatus for generating a cool air stream in which a blower is attached to a window of a building. A water delivering tube having a spray nozzle secured to its front side is detachably disposed in front of the blower, so as to eject water therefrom in the form of mist particles. Holders are attached to the window frame to provide a gap between each spray nozzle and the blower, and the holders are pivotally fitted to the water delivering tube by supporting means. In addition to the relatively complicated structure of the apparatus, other drawbacks concerning the performance of this spray device include inefficient usage of water and an inability to direct the mist to a predetermined location. Also, the apparatus is not capable of operating in an unenclosed area. Thus this apparatus, when employed in a dairy farm, cannot direct the mist to the hair coat of a group of cows, but rather humidifies the hot air, resulting in a waste of water.
U.S. Pat. No. 6,223,995 is directed to a method for cooling golf greens and other vegetation, using a fan with a tubular nozzle member fitted around the fan head.
Although prior art systems provide adequate cooling, they suffer from some drawbacks. Firstly, an inordinate amount of water is wasted. The cooling water is not necessarily directed at the cows, but rather it is discharged throughout a wide region, e.g. within the feeding area, so that an optimal number of heated cows will be cooled by the spray of water. In order to spray water throughout a wide region, a pump and steel pipes are needed so that water may be provided to a spray device at a pressure of approximately 40 atmospheres. Secondly, cows may not seek a spray-cooled comfort zone, and therefore the spray may not be effectively utilized. Water that does not impinge upon the hair coat of a cow falls to the ground. Thirdly, the water that falls to the ground generally collects as puddles and becomes a source of diseases to the cows, such as mastitis, especially in combination with cow droppings, despite the constant operation of a fan that additionally functions as a means to dry the ground.
None of the prior art methods and apparatus is adapted for concurrently cooling a plurality of cattle, particularly cows, more particularly cows in a shed. Each spray device of the prior art directs the spray at an area and not specifically at a cow or a plurality of cows. Additionally, the prior art does not take into account the influence of atmospheric conditions, particularly of the wind, which can divert any spray from its intended target and even render it totally ineffective and wasted. Any attempt to remedy these drawbacks by individually controlling each of the device that spray water would require the intervention of a very large number of operators, who are not available for such operations, and if they were available, would involve a wholly unacceptable manpower cost. This invention provides new method and apparatus for overcoming all the drawbacks and inadequacies of the prior art.